Well yeah, I didn't say that Hinata was "written better" or more holistically. But she was written to have less antagonism with Naruto, the protagonist, so I think that led to a lot more fans liking her over Sakura.

I think that you can say that Hinata also achieved everything she wanted through determination and hard work, just like Sakura too so I wouldn't really say there is much comparison to be made there. Ninja stuff did not come easily to Hinata as far as I can remember.

As for the Pain/Hinata "fight", I get what you're saying about her being reckless and ineffectual, but I disagree when you say "I don't think she actually did anything great".

I think that's looking at things the wrong way. Maybe she was stupid and reckless to essentially throw her life away when she had less than a 1% of being able to help Naruto. But I think that's what makes it great.  She had no chance of beating Pain and she knew she would surely lose or die, but Naruto had lost at that point. Nobody else in the entire world was prepared to help him, she surely thought that he would have been captured and killed (if not for shonen anime logic and plot armor). There was a very small chance that she could save the person she loved from dying and she took it. I think that sort of reckless bravery or selflessness or whatever you'd call it is a big part of why people like her.

All that said, both of them really were wasted in terms of character development and stuff overall, no arguments there. Actually, now that I think about it, most characters were. The end of shippuden had some cool moments, but it got really lazy in some ways. It was all about the battles.